Knife sharpener

ABSTRACT

A sharpener construction including a sharpener stone holder having an elongated body portion and a surface for receiving a sharpener stone with a plurality of concave depressions extending transversely to the stone receiving surface for receiving the fingers of a person, a screw attachment at the end of the elongated body portion for adjustably receiving the end of a guide rod which in turn is slidably received in preselected oval apertures in upstanding guides attached to the sharpener.

This is a division of application Ser. No. 325,757 filed Nov. 30, 1981,now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to an improved knife sharpener.

By way of background, sharpeners of the type shown in U.S. Pat. No.3,819,170 are known. In sharpeners of this type, a knife blade isclamped between two clamp members and a sharpening stone is guided alongthe edge of a blade by a rod member secured to a sharpener stone holderand guided through an aperture in an upstanding guide. However, theprior device was subject to certain deficiencies. The first deficiencywas that the hole through which the rod was guided was circular, therebylimiting the lateral sweep of the stone across the knife edge. Anotherdeficiency was in the sharpener stone holder itself. Firstly, the mannerin which the holder was held could result in cutting of the fingersbecause the fingers usually extended beyond the lower surface of thestone which contacted the knife edge. Secondly, the holder was held inan awkward position by only two fingers, thereby providing less controlthan if the holder was held with all of the fingers. Thirdly, thefingers produced more of a pushing motion of the stone toward the bladethan a downward motion causing the stone to bear against the edge of theblade, which in turn was more likely to result in an uneven sharpening.It is with overcoming the foregoing deficiencies of prior art types ofdevices that the present invention is concerned.

SUMMARY OF THE INVENTION

It is accordingly one object of the present invention to provide animproved knife sharpener in which relatively long blades can besharpened because of the fact that the knife sharpener stone is capableof being moved in a relatively large lateral sweep lengthwise of theblade.

Another object of the present invention is to provide an improvedsharpener stone holder for a sharpener which is securely grasped by allfive fingers to provide extremely good control during a knife sharpeningoperation.

A further object of the present invention is to provide an improvedsharpener stone holder which possesses a protective flange between thefingers and the sharpener stone to tend to prevent overhang of fingerswhich could be injured by the knife edge being sharpened.

A still further object of the present invention is to provide animproved sharpener stone holder which can be grasped with equal facilityby either the right or the left hand and which will provide all of theadvantages in either event.

Yet another object of the present invention is to provide a sharpenerstone holder gauging construction which effects automatic alignmentbetween the sharpener stone holder guide and the stone when the stone isnew and which permits adjustment as the stone wears and whichautomatically indicates when the stone has worn to the point at which itshould be replaced. Other objects and attendant advantages of thepresent invention will readily be perceived hereafter.

The present invention relates to a sharpener stone holder comprising anelongated body portion having a longitudinal axis and first surfacemeans extending lengthwise of the body portion for mounting a sharpenerstone, a plurality of concave second surface means extendingtransversely to said first surface means for receiving the fingers of aperson, and attachment means on said elongated body for mounting anelongated rod extending lengthwise of said body portion. The sharpenerstone holder of the present invention also includes flange meansproximate the juncture of the first and second surface means extendingtransversely to said second surface means for the purpose of protectingthe fingers against overhanging to the extent they could be cut by theknife edge being sharpened.

The present invention also relates to a sharpener stone holdercomprising an elongated body portion having a longitudinal axis andsurface means for mounting a sharpener stone extending lengthwise ofsaid longitudinal axis, a bore at one end of said elongated body portionextending transversely to said longituidnal axis, an elongated rodhaving a main portion and an end portion extending transversely to saidmain portion and being located in said bore, a flat on said end portion,a screw threadably mounted on said end portion transversely to andintersecting with said bore for bearing on said flat, and shoulder meansat the end of said flat for defining the limit of movement of said endportion in said bore by abutting said screw.

The present invention also relates to a sharpener constructioncomprising a pair of clamp members having a first longitudinal axis andfirst and second ends, a pair of jaws at said first end for clamping therear edge of a knife with a second longitudinal axis extendingtransversely to said first longitudinal axis, guide member meansextending outwardly from said clamp members at said second end, aplurality of apertures in said guide member means at different distancesfrom said second end for receiving a guide rod attached to a sharpenerstone holder, said apertures being oval in shape to allow for arelatively large lateral sweep of said guide rod.

The various aspects of the present invention will be more fullyunderstood when the following portions of the specification are read inconjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary plan view of the improved knife sharpener of thepresent invention mounting a knife to be sharpened and showing thesharpening stone holder in a plurality of positions;

FIG. 2 is a side elevational view taken substantially in the directionof arrows 2--2 of FIG. 1 and showing the sharpener stone holder in solidlines for sharpening one side of the blade edge and showing it inphantom lines for sharpening the other side of the blade edge;

FIG. 2A is a fragmentary enlarged view of the clamp end of thesharpener;

FIG. 2B is a cross sectional view taken subtantially along line 2B--2Bof FIG. 1;

FIG. 3 is a fragmentary end elevational view taken substantially in thedirection of arrows 3--3 of FIG. 1 and showing the oval holes forreceiving the sharpener stone guide rod;

FIG. 4 is a fragmentary cross sectional view taken substantially alongline 4--4 of FIG. 2 and showing the construction at the end of thesharpener stone holder for securing the guide rod therein;

FIG. 5 is a fragmentary cross sectional view taken substantially alongline 513 5 of FIG. 4;

FIG. 6 is a fragmentary enlarged view of a portion of FIG. 4; and

FIG. 7 is a fragmentary enlarged view of a portion of FIG. 5.

DESCRIPITON OF THE PREFERRED EMBODIMENTS

The sharpener 10 includes a knife clamp 11 and a sharpener stone holder12 which is operative therewith to sharpen the edge 13 of a knife 14which is held between jaws 15. Clamp 11 includes two clamp members 16and 17 which are secured to each other by means of a screw 19 whichextends through an aperture 20 in clamp member 17 and is threadablyreceived in tapped bore 21 of clamp member 16. A thumb screw 22 isthreadably received in tapped bore 23 of clamp member 17 and the end ofthumb screw 22 bears against the surface of clamp member 16 and isreceived in dimple or complementary depression 24 to prevent sidewisemovement of clamp members 16 and 17 relative to each other.

In order to secure a knife 14 within jaws 15 of clamp 11, screw 19 isbacked off sufficiently so that the distance between surfaces 25 and 26of jaws 15 receives the rear edge portion 27 of blade 14 with areasonably tight fit, and thereafter thumb screw 22 is manipulatd toforce clamp members 16 and 17 away from each other in the area of thumbscrew 22 so that the jaws 15 will tightly clamp the rear edge 27 ofknife 14 therebetween. The very outer edge portion of edge 27 will restagainst surfaces 29 and 30 of jaws 15.

A pair of guide members 31 and 32 extend upwardly from clamp members 16and 17, respectively. Guide members are fabricated from bent sheet metaland include upstanding main portions 33 and 34, respectively, and footportions 35 and 36, respectively, which extend substantiallyperpendicularly to the main portions and are formed integrallytherewith. Screws 37 and 39 extend through apertures in foot portions 35and 36, respectively, and are threadably received in clamp members 16and 17, respectively, to thereby secure the guide members 31 and 32 tothe clamp members.

A sharpener stone holder 12 includes an elongated body portion 43 whichis fabricated from molded plastic. It includes a planar surface 44extending substantially throughout the length of holder 12, and to whicha sharpener stone 45 is adhesively secured. A finger grip portion 46forms a part of body portion 43 and it includes a plurality of concaveindentations 47 on one side of ridge 49 and a symmetrical group ofconcave deformations 50 on the other side of ridge 49. In essencetherefore concave deformations 47 and 50 define wave-like surfaces. Aright-handed person would therefore place his four fingers inconcavities 47 and his thumb in the concavity which is also designated50'. A left-handed person would place his four fingers in concavities 50and his thumb in concavity which is also designated 47'. Therefore, thesharpener stone holder 12 can be manipulated with equal facility by aright-handed or a left-handed person.

Flanges 51 and 52 are molded integrally with ridge 49 and include thesymmetrical downwardly extending side portions 53 and 54, respectively,which bracket the sides 55 and 56 of stone 45. In addition, a downwardlyextending flange 57 (FIGS. 5 and 7) is located at one end of holder 12,as shown. The upper portions 59 and 60 of flanges 51 and 52,respectively, comprise shelves which serve as stops for the ends of aperson's fingers and thumb, thereby preventing them from extendingoutwardly beyond the lower surface 61 of stone 45 where the fingersmight engage the edge 13 of knife 14.

The sharpener stone holder 12 mounts a guide rod 40 at one end. Guiderod 40 includes a main guide portion 63 and an attachment portion 64which extends at substantially right angles thereto and which isreceived in a bore 65 in the end portion 66 of holder 12. A tapped metalinsert 67 is embedded in end 66 for receiving thumb screw 69. Attachmentportion 64 is inserted through bore 65, as shown in FIGS. 5 and 7, andthumb screw 69 is tightened so that the end 70 thereof bears againstflat 71 of attachment portion 64 to hold guide rod 40 in position.

The adjustment of guide rod portion 63 in the direction of arrows 72 and73 is effected by moving attachment portion 64 in the direction of thesearrows and thereafter tightening thumb screw 69. The ultimate objectiveis to have the edge of guide portion 63, as denoted by numeral 74,substantially in line with the surface 75 of stone 45. When the stone isinitially installed in the holder 12, surfaces 74 and 75 will be insubstantial alignment when shoulder 76 at the end of flat 71 is broughtinto abutting engagement with the end of thumb screw 69. As the stonewears, the attachment portion 64 will be moved gradually in thedirection of arrow 77 as the edge 74 is kept in alignment with the wornsurface 75. However, a point will be reached where surface 74 reachesthe dotted line position shown in FIG. 7 at which time shoulder 79 atthe end of flat 71 will abut the end of thumb screw 69, therebyproviding an indication that stone 45 has worn to the extent that itshould be replaced by either removing it from holder 12 or replacing itwith another holder-stone combination.

A plurality of oval apertures 33a-d are provided in guide 31 and aplurality of oval apertures 34a-d are provided in guide 32. Rod portion63 of rod 40 is inserted through a preselected aperture, for example,aperture 34a, as shown in FIG. 3, and the holder 12 is grasped in theabove described manner and the stone 45 is moved transversely andlongitudinally of edge 13 to sharpen it while the angle between the edge75 of the stone and the edge 13 of the blade is maintained constantbecause rod 63 is guided by the aperture in which it is located. Thedesired angle to be placed on edge 13 is selected by selecting which ofthe apertures in guides 31 and 32 is to be used. In use, first one sideof edge 13 is sharpened by causing guide rod 40 to xxtend through one ofthe holes in one of the guides 31 or 32 and thereafter the other side ofedge 13 is sharpened by causing rod 40 to extend through a correspondingaperture in the other of guides 31 or 32.

While preferred embodiments of the present invention have beendisclosed, it will be appreciated that the present invention is notlimited thereto, but may be otherwise embodied within the scope of thefollowing claims.

What is claimed is:
 1. A sharpener stone and holder comprising anelongated body portion having a longitudinal axis, surface means on saidelongated body portion, a sharpener stone mounted on said surface meansand extending lengthwise of said longitudinal axis, a sharpening surfaceon said sharpener stone, a bore at one end of said elongated bodyportion extending transversely to said longitudinal axis, an elongatedrod having a main portion and an end portion extending transversely tosaid main portion and being located in said bore, a flat on said sendportion, a screw threadably mounted on said elongated body portion andextending transversely to and intersecting with said bore for bearing onsaid flat, said flat permitting said main portion to be aligned withsaid sharpening surface as the latter wears while said screw maintains abearing relationship with said flat, and shoulder means at the end ofsaid flat for defining the limit of movement of said end portion in saidbore by abutting said screw, to thereby indicate that said sharpeningsurface has worn to the extent that it should be replaced.
 2. Asharpener stone holder as set forth in claim 1 wherein said shouldermeans comprises first and second shoulders at the end of said flat.
 3. Asharper stone and holder comprising an elongaed body portion having alongitudinal axis and elongated planar first surface means extendinglengthwise of the body portion, a sharpener stone mounted on said firstsurface means, second and third surface means on the outer sides of saidelongated body portion extenidng in a direction transverse to saidelongated planar first surface means, first and second concaveindentation means in said second and third surface means, respectively,said first and second concave indentation means defining wave-likepatterns extending longitudinally of said elongated body portion forreceiving the finger tips of a person on said second surface means andfor receiving the end of the thumb of a person on said third surfacemeans, attachment means on said elongated body for mounting an elongaedrod extending lengthwise of said body portions, said shapener stoneincluding a sharpening surface, said attachment means comprising a boreextending transversely to said longitudinal axis proximate the end ofsaid elongated body portion, an elongated rod having a main portion andan end portion extending transvesely to said main portion and beinglocated in said bore, a flat on said end portion, a screw threadablymounted on said end portion transversely to and intersecting with saidbore for bearing on said flat, said flat permitting said main portion tobe aligned with said sharpening surface as the latter wers while saidscrew maintains a bearing relationship with said flat, and shouldermeans at the end of said flat for defining the limit of movement of saidend portion in said bore by abutting said screw, to thereby indicatethat said sharpening surface has worn to the extent that it should bereplaced.
 4. A sharpener stone and holder comprising an elongated bodyportion having a longitudinal axis and elongated planar first surfacemeans extending lengthwise of the body portion, a sharpener stonemounted on said first surface means, second and third surface means onthe outer sides of said elongated body portion extending in a directiontransverse to said elongated planar first surface means, first andsecond concave indentation means in said second and third surface means,respectively, said first and second concave indentation means definingwave-like patterns extending longitudinally of said elongated bodyportion for receiving the finger tips of a person on said second surfacemeans and for receiving the end of the thumb of a person on said thirdsurface means, attachment means on said elongated body for mounting anelongated rod extending lengthwise of said body portion, first andsecond flange means on opposite sides of said elongated body portion andproximate the juncture of said first surface means with said second andthird surface means, respectively, and extending outwardly from saidsecond and third surface means for serving as stops for said ends ofsaid finger tips and said end of said thumb, respectively, saidsharpener stone being located to one side of said first and secondflange means and said second and third surface means being located onthe opposite side of said first an second flange means from saidsharpener stone, said first and second flange means preventing said endsof asid fingers and said end of said thumb from extending outwardlybeyond said sharpener stone.
 5. A sharpener stone and holder as setforth in claim 4 wherein said sharpener stone includes opposite sides,and first and second side portions extending downwardly from said firstand second flange means for engaging said opposite sides of saidsharpener stone.